Polar cod face new threat from Arctic oil pollution

Hard to find, hard to research, but a key player ecologically: The polar cod is a highly vulnerable Arctic species. Image: By Wikifranky, via Wikimedia Commons

 

Already struggling to survive in warming Arctic seas, the polar cod are now at risk from rising oil pollution.

They are small – on average around 25cm long. But polar cod (Boreogadus saida) are a vital part of the Arctic food chain, a major ingredient in the diet of seals, narwhals and a wide variety of seabirds.

The Arctic is warming faster than any other area on the planet, and a study published in 2020 found that declines in winter sea ice cover in the Barents Sea region of the Arctic, plus warmer sea temperatures, were causing declines in polar cod reproduction rates.

The latest research indicates that the polar cod is now under threat not only from warming Arctic seas, but because of oil pollution as well, as the region’s rapidly diminishing ice cover allows more shipping traffic and commercial activity.

Morgan Lizabeth Bender is a researcher in the department of Arctic and Marine Biology at the University of Tromsø (UiT) in northern Norway. Her research has found that when the polar cod is exposed to a combination of warmer waters and only very slight levels of oil pollution, its development is interrupted, with abnormalities common.

“Polar cod is a somewhat difficult species that hasn’t been researched that much,” Dr Bender told the Science Norway website. “The fish are a difficult species to find and to take care of in the lab. However, this species has a very important ecological role.”

“Increased water temperature can increase the harmful effects of oil exposure”

The fish, monitored during the breeding process, were sorted into aquariums – some at a current Arctic water temperature of 0.5°C, others at a warmer 2.8°C to mimic an Arctic affected by climate change.

The aquariums contained either pure water or water contaminated by minuscule amounts of crude oil. “The pollution level would be the equivalent of about five drops of oil in an Olympic-size swimming pool,” says Dr Bender.

Though the study found that polar cod eggs in the warmer water hatched much faster than those in the colder water, at first there was little difference between survival rates in the various aquariums.

But then something strange started happening to the fry – the young fish – that were exposed to oil.

“When they first hatched, there wasn’t much difference,” says Dr Bender. “But as their jaw, face and eyes started to develop, we saw very clearly that they weren’t forming properly.”

Lower survival rates

The research found that the fry were very sensitive to even the slightest amount of oil pollution: death rates were highest among fry exposed to both warmer water and oil.

When the fry became large enough to start feeding, only 8% survived in the contaminated warmer water and 23% in the contaminated cold water.

Marine scientists say that polar cod numbers have shown a downward trend since 2010, despite the fact that they are not a fished species.

Sonnich Meier, of the Norwegian Institute of Marine Research, has been examining the impact of both global warming and oil pollution on Arctic fish species for a number of years.

“Polar cod is one of the fish species that is hardest hit by climate change in the Arctic,” he says. “The study shows that increased water temperature can increase the harmful effects of oil exposure.” – Climate News Network

About the Author

cooke kieran

Kieran Cooke is co-editor of the Climate News Network. He is a former BBC and Financial Times correspondent in Ireland and Southeast Asia., http://www.climatenewsnetwork.net/

This Article Originally Appeared On Climate News Network

YOU MAY ALSO LIKE

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

image
Why the UK is so unprepared for the impacts of climate change
by Liam F. Beiser-McGrath, Lecturer (Assistant Professor) in Politics and Director of the PECC Lab, Royal Holloway University of London
The UK is woefully unprepared for the dangers of climate change according to a report from the Climate Change Committee…
Rows of solar panels are separated by a walkable space between them
Solar power and energy storage combo boosts reliability
by Matt Shipman-NC State
New research shows that when a power system combines energy storage and solar power generation, the end result is…
Climate change: what G7 leaders could have said – but didn't
Climate change: what G7 leaders could have said – but didn't
by Myles Allen, Professor of Geosystem Science, Director of Oxford Net Zero, University of Oxford
The four-day G7 summit in Cornwall ended with little cause for celebration from anyone worried about climate change.…
How world leaders' high-carbon travel choices could delay climate action
How world leaders' high-carbon travel choices could delay climate action
by Steve Westlake, PhD Candidate, Environmental Leadership, Cardiff University
When UK prime minister Boris Johnson took a one-hour flight to Cornwall for the G7 summit, he was criticised for being…
Maggot burgers can help to solve world hunger
by Paul Brown
Fancy maggot burgers for dinner? Eating animals and plants which revolt many of us could cut hunger caused by climate…
The idea of green growth'is flawed. We must find ways of using and wasting less energy
by Michael (Mike) Joy, Senior Researcher; Institute for Governance and Policy Studies, Te Herenga Waka — Victoria University of Wellington
As countries explore ways of decarbonising their economies, the mantra of “green growth” risks trapping us in a spiral…
Four reasons why G7 climate finance initiative will struggle against China's Belt and Road
Four reasons why G7 climate finance initiative will struggle against China's Belt and Road
by Karen Jackson, Senior Lecturer in Economics, University of Westminster
During the G7 summit in Cornwall, the group of nations unveiled a global initiative to help low and middle-income…
image
Electric heat pumps use much less energy than furnaces, and can cool houses too – here's how they work
by Robert Brecha, Professor of Sustainability, University of Dayton
To help curb climate change, President Biden has set a goal of lowering U.S. greenhouse gas emissions 50%-52% below…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.